A way this analogy breaks down is that lazyness evaluates precisely what is needed, and no more. The set of values evaluated by lazyness is exactly equivalent to the set of values needed. Garbage collectors are conservative by nature, the values collected by the garbage collector are some subset of the values that will not be needed in the future, which particular subset that is depends on details of the garbage collector and the optimizer. Also, there is no real direct way to "observe" _when_ values have been garbage collected (without resorting to weak pointers or implementation details) so it is questionable what a correspondence will give you practically in terms of reasoning ability. Whether the garbage was 'collected' right away or when needed, as long as you don't run out of memory the program is oblivious to it. John -- John Meacham - ⑆repetae.net⑆john⑈